Heat the oil in a frying pan, reduce the heat, fry the aubergine for approx. 10 mins., remove from the heat, season with salt and set aside.
Heat the oil in a frying pan, sauté the onion for approx. 5 mins. Add the pepper and all the other ingredients up to and including the olives, season, cover and simmer over a low heat for approx. 25 mins. Add the balsamic, sugar and reserved aubergine, cover and simmer for a further 15 mins. Mix in the pine nuts and capers, serve the caponata lukewarm.